The Question:

Is the monkey wrench named for a man named Moncky?

The Answer:

The invention of the monkey wrench has been
attributed to a man named Charles Moncky, who is said to have created
it in the mid-19th Century. The claim is that the "Moncky wrench" got
corrupted to "monkey wrench." Sadly, this claim is incorrect; the
wrench was around, and so named, before Mr. Moncky came along.

The true origin of the name is unknown, though if you open one
up a bit and use a great deal of imagination, its head might vaguely
resemble that of a primate.